Product Reviews

The latest FAS3020 from storage guru Network Appliance (NetApp) takes network storage to the next level, as it amalgamates SAN, NAS and iSCSI IP SANs into a single package. Even better is the fact that its licensing system allows you to pay as you go. So you could, for example, start off with support for Fibre Channel (FC) SANs and add NAS file sharing and iSCSI support as and when required.

The FAS3020 on review delivers impressive expansion potential. The 3U controller comes with a quartet each of copper Gigabit Ethernet and 2Gb/sec FC ports. But it also has three spare PCI-X slots ready to take a mixture of additional copper or Fibre Gigabit Ethernet and 2Gb/sec FC cards. The fourth slot is occupied by NetApp's proprietary controller card, which supplies battery-backed-up NVRAM cache memory. This works in tandem with the Data ONTAP OS, which is implemented on a CompactFlash card and provides software-managed RAID functions. The chassis has dual redundant power supplies and fans, and NetApp's NVRAM card has external ports to allow a pair of FAS3020 chassis to be clustered.

Storage is provided by NetApp's DiskShelf14 disk arrays, which have room for 14 hard disks apiece and are offered in either FC or SATA variants. For the review, we were supplied with the FC version equipped with a full set of 147GB Hitachi drives in hot-swap carriers. The chassis offers two pairs of mini-GBIC ports and up to 12 arrays can be chained to one FAS3020 controller, so opting for 300GB FC hard disks allows total storage capacity to go up to a healthy 50TB.

Management using the tidy web interface is easy enough and there are plenty of wizards to hand. However, it's worth taking a moment to understand the NetApp technique before creating your network storage. The FAS3020 employs a RAID4 implementation that the company calls an aggregate. This comprises multiple data drives teamed up with a parity drive. The reason for this is that more drives can be added to aggregates on-the-fly, and if a data drive fails then the parity drive maintains consistency. Should the parity drive fail, data can still be accessed and it's possible to designate a second parity drive as well.

Adding

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storage to the network is a tad more complicated than some, although it does offer significant benefits. From your aggregate, you create volumes that are automatically striped across the physical drives, and these can have quotas at the user or group level applied to them. The FAS3020 supports snapshots and global settings determine the percentage of the volume to be kept aside for them, whether they should be made visible as a separate directory and how often during each day they're to be run automatically.

If you're going for NAS, you create a share and simply add a volume mount point, but SAN and iSCSI differ, since you need to create a LUN (logical unit number) first. Next, you decide which type it will be and then assign an initiator group to it. The latter allows you to determine which clients are allowed to access specific LUNs. However, it's a bit of a pain to enter each FC WWN (world wide name) and iSCSI IQN manually, as these aren't displayed in the web interface.

The FAS3020 impressed us during performance testing, though. After an introduction to our resident 2Gb/sec FC SAN built from a QLogic SAN Connectivity Kit, we direct-attached a Windows Server 2003 system to one port via a QLA2310 FC HBA. Running the open-source Iometer configured with two disk workers, 64KB transfer requests and 100 per cent sequential reads, we saw the server return an impressive 191MB/sec average transfer rate, which is close to the limit of 2Gb/sec FC. We created another FC LUN, assigned it to a second Windows Server 2003 system and saw Iometer return a cumulative 380MB/sec for the two systems, showing no drop in performance across the two systems.

Speeds for iSCSI were even more impressive. We created a single iSCSI LUN and used a Server 2003 system with the Microsoft iSCSI initiator 1.06 installed. With the server's IQN added to the appropriate initiator group and assigned to the LUN, we were able to access the virtual disk as though it were a local drive. Rerunning Iometer returned a remarkable 110MB/sec. Adaptec's Snap Server 18000 had held the record for iSCSI speed over a single connection at 107MB/sec, but the accolade now goes to NetApp.

Along with this fine performance, NetApp's Data ONTAP OS offers a wealth of optional features that are activated simply by adding new licence keys at the web interface. Along with fail-over clustering, you can add mirroring between remote sites, a SnapLock feature for permanently securing critical business information and volume cloning.

The FAS3020 offers SMEs one of the most comprehensive network storage solutions currently available. Storage capacity can be easily expanded on-the-fly and, although you're paying for the privilege, performance across the board doesn't get any better than this.